A motorcycle exhaust structure is known, wherein a main frame extending downward obliquely and backward from a head pipe supporting a front wheel is provided. A V-type engine is held under the main frame. An exhaust pipe extending from a cylinder of the engine is connected to a muffler divided into two portions before and after an oil pan under a crankcase. The rear muffler portion is larger than the front muffler portion (see JP-A No. 2004-26007).